PRESIDENT Rodrigo Duterte may be forced to expand the declaration of martial law in case of a spillover of terror acts into areas outside of war-torn Mindanao, Malacañang said Thursday, July 18.

"He (Duterte) can declare martial law. He can declare revolutionary government. He can use other emergency powers under the Constitution to quell whatever violence or any attempt at destroying this Republic," Presidential Spokesperson Salvador Panelo said in a press conference with Palace reporters.

"Pwede niyang gawin lahat yun (He can do everything). The military or all the Armed Forces of the Philippines, under the Constitution, are obligated to protect the people. The President can use the Armed Forces of the Philippines," he added.

Mindanao has been placed under martial rule until December 31, 2019, after Islamic State-affiliated Maute terrorist group laid siege to besieged Marawi City in Lanao del Sur province on May 23, 2017.

Panelo's statement came after military's bomb-sniffing dogs detected traces of explosives in an abandoned motorcycle outside the gate of the Philippine Army headquarters in Taguig on Wednesday, July 17.

The latest incident follows nearly three weeks after the twin blasts that rocked Indanan, Sulu, killing at least eight people, including three soldiers.

The police and the military have confirmed that one of the two alleged suicide bombers in deadly explosions in Sulu on June 28 is a Filipino.

Panelo said Duterte was "very concerned" about the supposed involvement of a Filipino in the twin bombings in Sulu.

"Kaya nga diba (That's why he said), 'Don't force me to the wall. 'Pag hindi kayo tumigil (If you don't stop), I'll be compelled to use powers granted to me by the Constitution, lalung lalo pa 'yung terrorismo makarating dito sa Maynila (especially when terrorism spreads to Manila),"he said.

"'Yun nga ang kinakatakot niya kasi may suicide bomber na. He's very concerned about that. Kaya 'di ba nag-warning siya sa enemies of the state, 'Don't force my hand into it. I will not allow the disintegration of this country,'" Panelo added.

(He's afraid of such possibility because there is already a Filipino suicide bomber. He's very concerned of that. That's why he issued a warning to the enemies of the state, "Don't force my hand into it. I will not allow the disintegration of this country.")

On July 10, Duterte expressed his intent to boost the defense capabilities of the military and the police forces, as he warned against possible looming terror threat in the country.

Quizzed if the Commander-in-Chief has already reached a point to decide on possible expansion of martial law, Panelo said: "Sabi niya nga (He said) he doesn't want to be forced into it." (SunStar Philippines)